What should the next step.
3 wires of ground? A receptacle would have two power wires and one safety ground. Safety ground does nothing to protect hardware and does nothing to make a protector effective. It exists to protect you (human life).
That wall receptacle safety ground is completely different from earth ground. A homeowner is responsible to know what earth ground is and to maintain it.
Find a bare copper, quarter inch hardwire that goes from the mains box (power board), outside, to an earth ground electrode. If that does not exist, then no effective protection is possible. And a serious human safety issue also exists.
All was simplified to a 'high school science knowledge' level. But since new, then it must be read at least three times. Rephrasing same here may help.
A 'whole house' protector is required to protect computers, to protect any plug-in protector, and to protect all other 'just at risk' or 'at greater risk' appliances. Including a dishwasher, clocks, refrigerator, garage door opener, LED & CFL bulbs, furnace, recharging electronics, dimmer switches, central air (even when not in use), and every smoke detector.
Everything posted was learned in school. High school math was defined. What Ben Franklin demonstrated was taught in elementary school science. What Franklin demonstrated is also what protects appliances and computers. What Franklin demonstrated does not require expert language. What Franklin demonstrated is also what you must do to properly earth every incoming utility wire via a 'whole house' protector.
That 'whole house' protector protects appliances for the same reason that Franklin's lightning rod protects a structure. In both cases, protection is only as effective as (is defined by) earth ground.
Go to any big box hardware store or electrical supply house. Ask the 'whole house' protector that they sell. Then confirm it is at least 50,000 amps. (Honesty is impossible without numbers.)
Last paragraph ('effective protector sold like rice') defines what must be purchased to effectively connect incoming utility wires to earth. Best protection is distant from every appliance and as close as possible to earth ground.